This study aims to fill two important gaps in the present knowledge of adolescent substance abuse and other problem behavior: 1) Its phenomenology, i.e. the meaning of such problem behavior to adolescents in relation to other aspects of their lives, and 2) the socio-economic status (SES) determinants and concomitants of that phenomenology, i.e. how adolescent self perspectives vary with socio-economic status. 1) Little research ow speaks to the phenomenology of problem behavior -- the inner experience of young people which may pull them towards it, protect them from it, or guide them through experiment, doubt and confusion over it. This study will do so by comparing how adolescents' views of themselves, their relationship, and their future prospects, hopes and expectations affect their involvement with and interpretations of substance abuse and other problem behavior (sexual precocity, school dropout, and delinquency) as well as psychological states such as anxiety and depression. 2) Previous studies of these problems have not used the same instruments on upper- and lower-SES groups. Questionnaire studies have typically surveyed middle class adolescents only, using instruments whose idiom is foreign to many inner-urban youngsters and which requires literacy beyond that of many young people at risk. This study will use a standard questionnaire and interview combination developed on and suitable to both upper- and lower- SES groups. The knowledge gained from this study can contribute to the development of adolescent peer leadership programs, counseling training programs, and the curricula for "problem awareness" and other substance abuse and problem behavior prevention and intervention programs for youth. Intervention efforts to curb substance abuse and related problem behavior run increased risk of failure if they are uninformed by young peoples' perspectives on such problems.